1. Field of the Related Art
The present disclosure relates to document processing services, such as printing systems, and more particularly, to a method and system for automating quality assurance for one or more documents.
2. Background of the Related Art
In a conventional reproduction device, a document or image is scanned by a scanner which converts the light reflected from the document into electrical charges representing the light intensity from predetermined areas (pixels) of the document. The pixels of image data are processed by an image processing system which converts the pixels of image data into signals which can be utilized by the digital reproduction machine to recreate the scanned image. In other words, the image processing system provides the transfer function between the light reflected from the document to the mark on the recording medium.
One measure of the performance of a reproduction machine is how well the copy matches the original. Copy quality can be measured in many different ways. One way is to look at the characteristics of the reproduced image. An example of such a characteristic for determining the quality of the reproduced image is the contrast of the image. The contrast of an imaged (copied) document is one of the most commonly used characteristics for measuring quality since contrast provides a good overall assessment of the image's quality. However, visual quality assurance can be cumbersome and expensive.
Furthermore, electronic documents, such as those created using many document and/or word processing applications, generally have several layers of data. Each layer in the document, termed a “document layer,” contains some information related to the document or its contents. For example, the text seen by an end user creating, editing, or viewing a document may be represented in one layer of a document. Another layer may contain some of the drawings and/or figures that are part of the document. Finally, a third layer may contain the background over which the text and drawings are displayed. A layer may be changed without requiring any change in other layers associated with the document.
However, in addition to the layers described in the example above, a document may also contain “invisible layers.” These invisible layers may contain data pertaining to the document or its contents rather than actual document content that is seen by users. Such data may be referred to as glyphs. Glyphs are graphical indicia that are used to encode digital information to print duplicated versions of a digital image on a single document. Glyphs and encoding of layers are known in the prior art.
For example, U.S. Pat. No. 7,397,584 to Harrington, which issued on Jul. 8, 2008, describes a printed image that can be redundantly encoded by printing a visible image by using a colorant with a luminance that contrasts with that of the output sheet and printing a redundant image using a colorant with a luminance that varies only slightly from that of the output sheet. Accordingly, the visible image can be easily read by a user while the redundant image is substantially invisible to the human eye at normal-reading distances, yet capable of being captured by a conventional digital scanner. In one aspect, redundantly encoded images may be printed on a white background, with visible images printed in black text and redundant images printed in blue in content regions of the visible image and in yellow in its background regions.
Therefore, during the process of scan capturing documents, scanned images are traditionally verified by having the document owner or scan operator look at each document image as part of a quality assurance (QA) process. In addition, invisible layers may be added to a document for improving scanning functionality. Nevertheless, visual quality assurance is a cumbersome, error prone, and expensive process, and glyphs are highly visible and thus, they often detract from the visual appearance of the document.